"I feel like there's not enough clothing out there to show our personality, and just to be comfortable and to be fashion-forward and to be a trendsetter," the designer, 24, tells PEOPLE. "There are a lot of clothes out there for the straight-size woman to be able to show that, but in the plus-size industry, I don't feel like it's there just yet."
Tipton – who is the first designer to appear on the show that specializes in plus-size apparel – was actually inspired to pursue her dreams by all the bullies who told her she'd never succeed at anything.
"When people told me that I couldn't do something, I wanted to always prove them wrong," she says. "That comes a lot from people always bullying me because of my size, and not thinking that I could do anything to impact the world or inspire other people. I feel like this first episode is showing that what they've done to me in the past does not affect who I am. I'm still going to do what I want to do."
Still, she admits that her former bullying still weighs negatively on her self-esteem, which is something she struggled with while filming.
"Being bullied young, it definitely brought up a lot of insecurities, and it's taken me a long time to get rid of those insecurities, and I'm still learning today," says the San Diego native. "Going onto this show, I really had to have faith in myself and believe in myself that I could do this, because I knew going into it that at any point, it could trigger these insecurities that I've had."
Ashley Tipton's Project Runway Casting Video
Tipton decided to push past her insecurities and audition for Project Runway after a tragic death in her family.
"I lost my grandma two days before I auditioned," she says. "She taught me how to sew at a young age, and I felt like I had nothing else to lose, so I might as well take this chance. I'm very, very glad that I did."
While Tipton is used to designing for plus-size women, she liked being able to design for straight-size women for the show's challenges.
"I think the hardest thing is to design for plus-size women," she explains. "I enjoyed designing for straight-size because there's no limits. They can basically wear anything, and that's where I was able to have creative freedom with it."
No matter whom she's designing for, Tipton is sure to incorporate her unique aesthetic.
"I like to design funky things, and I love to mix prints and patterns together," says Tipton. "I think outside of the box with my designs."
Project Runway premieres Thursday at 9 p.m. ET on Lifetime.